Head Lice
Public Health – Factsheet
What are head lice?
Head lice are small insects that live on people’s heads
and feed on human blood. Head lice may be found
anywhere on the head, but are usually found on the
scalp, along the neckline and behind the ears.
What are the symptoms of head lice?
You may get a tickling feeling on your head. When
lice bite the scalp, it may cause itching and sometimes
redness. Itchiness does not always mean that a person
has head lice as other things can cause an itchy scalp.
It is also possible to have head lice and not have any
symptoms.
Can head lice cause disease?
Head lice do not cause or carry disease. Scratching
an itchy scalp may break the skin and cause infection
but this does not happen often. Head lice are not a
health hazard. They are very common and are not a
symptom of poor hygiene.
What do head lice and their eggs look like?
Adult head lice are about the size of a sesame seed.
They have six legs and are usually tan, grayish white
or brown in colour. Head lice can crawl quickly
through the hair and are difficult to spot. They do not
have wings and cannot fly or jump.
Head lice lay their eggs on the hair shaft very close
to the scalp with a waterproof “glue.” This makes
it difficult to wash them off or brush them out like
dandruff. When the eggs hatch, the empty eggshell
is left. This is called a “nit.” The nit remains stuck to
the hair shaft. It is hard to tell the difference between
an egg and a nit. Eggs that have hatched (nits) are
sometimes easier to see than unhatched eggs because
they appear white in colour against dark hair.
Dandruff, scabs and other hair debris are sometimes
mistaken for lice, eggs or nits.
MG-15440 August 2014
Actual size of the three lice forms compared to a penny (CDC Photo)
How do you get head lice?
Head lice are spread by head-to-head contact with
someone who has head lice. It is possible to spread
lice by sharing personal items that have recently
touched the head of someone with lice – such as hats,
combs and brushes – but this is much less likely. Head
lice cannot be spread to people from pets or other
animals.
Who gets head lice?
Anyone with scalp hair can get head lice. Head
lice may also be found on people’s eyebrows and
eyelashes. It is more common among young children
attending child care facilities and elementary schools
as well as household members of children who have
head lice. Clean hair offers no protection against
getting lice. Head lice are not a symptom of poor
hygiene.
How can you tell if a person has head lice?
At least one moving head louse (singular for lice) must
be found on the head. Finding eggs or nits does not
mean that a person has active head lice. Other things
can cause an itchy scalp, so itchiness alone does not
mean a person has head lice.
Head Lice
What is the best way to look for head lice?
Combing the hair by a parent or family member is a
good way to look for lice.
1. Wash hair well with ordinary shampoo and leave
damp. Wet hair slows down the lice, making
them easier to remove. Soaking the hair with oil
or conditioner from the scalp to the ends may
make combing easier.
2. In good light, comb the hair with a wide-toothed
ordinary comb to straighten and de-tangle the
hair.
3. Switch to a fine-toothed lice comb. You can buy
these combs at pharmacies and can ask the
pharmacist for help in choosing one. Work
through the hair in small sections, starting with
the skin of the scalp/roots at the top of the head
and comb through to the ends of the hair.
4. Check for moving lice with every stroke. Wipe the
comb after each stroke with a tissue and place
tissues in a bag.
5. If you are not sure if you have found a louse, use
clear tape to attach it to a piece of paper. Show
this to your health care provider or other person
trained to identify live head lice.
6. Repeat steps 3 to 5 until all of the hair on the
head has been combed.
7. Tie up the bag with used tissues and throw it in
the garbage.
8. If moving lice are seen, wash all of the conditioner
or oil out and start treatment.
Who should I tell if my child has head lice?
• The parents of other children who your child has
recently played with and may have had head-tohead contact with.
If a child in school or child care facility has
head lice, do they need to be sent home?
No. Head lice are not spread that easily. A child with
an active head lice infestation has probably had the
infestation for a month or more. It can take that long
before the scalp begins to itch. Infested children
usually carry less than 10 lice. The child with head
lice should not have head-to-head contact with others.
How is head lice treated?
Treatment should not be started unless there is at least
one live louse found. Lice treatments can be bought
at pharmacies without a prescription. Treatments or
medicines that kill lice are called pediculocides.
Some treatments may also kill lice eggs. Treatment
with a lice product that has permethrin or pyrethrin
as the active ingredient is recommended. Other
lice treatments that work well have dimeticone or
isopropyl myristate as the active ingredient.
1. Read the directions on the package carefully and
follow instructions. Some products cannot be
used on young children, pregnant women or
people with certain allergies. If the directions state
that the product should not be used on the person
needing the treatment, contact your health care
provider or pharmacist for advice.
2. Rubber gloves may be used to avoid coming into
contact with the lice product.
3. Do not leave the lice treatment on for longer than
stated in the package directions.
4. Do not use more or less of the product than
directed.
5. Do not use lice treatment on open or infected
skin.
• Your child’s child care provider or teacher as there
may have been head-to-head contact with other
children through work or play.
6. Keep the product out of the eyes. A facecloth may
be placed over the face to help prevent the product
getting into the eyes. If the product gets into the
eyes, flush eyes right away with lots of water.
• Alerting others allows them to check for lice and
treat promptly if lice are found. This will reduce
spread to others.
7. Rinse the product out of the hair over a sink, not
in the shower or bath, so that the product does
not get onto other skin.
8. After treatment, comb out any remaining lice with
a fine-toothed nit comb. Nit combs can be bought
at pharmacies.
Head Lice
9. After treatment, the person treated for lice should
put on clean clothing.
10.Comb hair 24 hours after treatment with a
fine-toothed nit comb. If moving lice are still
found 24 hours after the first treatment, contact
your health care provider or pharmacist for help.
You may need to re-treat with a different product.
11.If the first treatment appears to have worked and
no moving lice are found 24 hours after
treatment, repeat the treatment in seven to 10
days to kill lice hatching from eggs that were not
killed with the first treatment.
Why does the treatment sometimes not
work?
People may not follow the instructions on the package
properly. They may use too much or too little lice
treatment or they may leave the treatment on for too
long or not long enough. They may do the second
treatment too soon or too late. Sometimes lice develop
resistance to the treatment. Your health care provider
or pharmacist can help you find another treatment if
they think the lice were resistant to the first treatment.
Does the treatment have any side effects?
The scalp might become itchy after the lice treatment.
This does not mean that the treatment did not work.
An anti-itch medicine may help.
Eggs and nits are firmly glued to hair shafts and are
not likely to fall off and infest other people. People
may want to remove nits for aesthetic reasons. If you
decide you do want to remove eggs/nits, they can
be pulled off with your fingernails or by cutting and
removing a single strand of hair between the scalp and
where the eggs/nits are. A nit comb may help.
How can I get rid of head lice from my
home?
Head lice live for less than two days if away from the
higher temperature of the scalp. Eggs will not hatch
away from the higher temperature of the scalp and
they usually die within a week.
• Soak all combs and brushes in hot water (at least
55°C or 130°F) for five to 10 minutes.
• Wash items in contact with the head (example:
hats, pillowcases) in the past 48 hours in hot
water and dry in a hot dryer for at least 15
minutes.
• Dry clean or store non-washable items in an air
and water-tight plastic bag for two weeks.
Freezing temperatures can also kill head lice and
eggs but several days may be needed depending
on temperature and humidity.
What should I do to prevent getting head
lice?
Do other treatments work?
• Avoid head-to-head contact with a person who
has head lice.
There is no proof that home or natural remedies
such as vinegar, olive oil, mayonnaise, melted butter,
petroleum jelly, tea tree oil or eucalyptus oil work.
• Avoid using items that have been in contact with
the head of a person with head lice such as hats,
combs, brushes, hair accessories and pillowcases.
Lice removal combs may be used on wet hair to
physically pull out lice and their eggs. This is similar
to combing to look for head lice. Wet hair slows
down the lice, making them easier to remove. This is
time consuming as the wet hair combing should be
repeated every few days for a period of two weeks.
This has been called “wet-combing” or “bug-busting”.
• Have someone check your head if you have been
in contact with someone who has head lice. If lice
are found, they can be treated right away.
Do all of the eggs and nits need to be
removed after lice treatment?
No. The two treatments seven to 10 days apart
should get rid of all live lice, including any lice that
may hatch from eggs that survive the first treatment.
For more information
Talk to your health care provider, your local Public
Health Unit or call Health Links-Info Santé in
Winnipeg: 204-788-8200; toll-free (outside
Winnipeg): 1-888-315-9257. Information is also
available on the Manitoba Health website at:
www.gov.mb.ca/health/publichealth/headlice.html.
Head Lice